This is a comprehensive up-to-date treatise including information on virus-, viroid-, and phytoplasma-induced potato diseases. The chapters of this book were written by internationally well-known experts and include novel techniques of detection, virus isolation, transmission, and epidemiology of the pathogens.

Precise regulation of gene expression in both time and space is vital to plant growth, development and adaptation to biotic and abiotic stress conditions. This is achieved by multiple mechanisms, with perhaps the most important control being exerted at the level of transcription. However, with the recent discovery of microRNAs another ubiquitous mode of gene regulation that occurs at the post-transcriptional level has been identified. MicroRNAs can silence gene expression by targeting complementary or partially complementary mRNAs for degradation or translational inhibition. Recent studies have revealed that microRNAs play fundamental roles in plant growth and development, as well as in adaptation to biotic and abiotic stresses. This book highlights the roles of individual miRNAs that control and regulate diverse aspects of plant processes.

Soils into which crop plants root and from which they obtain essential minerals and water contain huge arrays of microbes. Many have highly beneficial effects on crop growth and productivity, others are pathogens causing diseases and losses to yield and quality, a few microbes offer protection from these pathogenic forms and others have little or no effect. These intimate and often complex inter-relationships are being explored with increasing success providing exciting opportunities for increasing crop yields and quality in sustainable harmony with the populations of beneficial soil microbes and to the detriment of pathogens. This book explores current knowledge for each of these aspects of soil microbiology and indicates where future progress is most likely to aid in increasing crop productivity by means which are environmentally benign and beneficial.

Around the globe, besides fungal and bacterial diseases, both virus and viroid diseases have acquired greater importance in the realm of plant pathology and call for effective management measures as they are responsible for heavy yield losses and are a matter of vital importance and concern to farmers, horticulturists, gardeners and foresters. Understanding disease epidemiology is of vital importance for formulating viable disease management practices in a given agro-ecosystem. The development and progress of plant disease epidemics are variable from region to region. Epidemiology is not a static process, but rather a dynamic course that varies with a change in the ecology, host, vector and virus systems.

For investigators engaged in the study of toxins generally, and host-specific toxins in particular, it is a rare treat to attend a meeting in which toxins involved in plant pathogenesis are emphasized. A gathering of this type provides opportunity to consider the discovery of new toxins, their chemical structures, genes encoding enzymes that control their biosyntheses, their sites of action and physiological effects on plants, and their roles (if any) in pathological processes. Having acknowledged the inspiration fostered by a 'toxin meeting', however, it is important to point out that the program of this symposium was generously sprinkled with 'nontoxin' talks. These contributions generated cross-disciplinary discussion and promoted new ways of thinking about relationships among factors required for plant disease development. The point can be illustrated by considering just one example. We have in the past often regarded diseases mediated by host-specific toxins and diseases involving 'gene-for-gene' relationships as representing two different classes of fungal/plant interaction. This is largely because the key molecular recognition event in so-called 'toxin' diseases leads to compatibility, whereas the corresponding event in 'gene-for-gene' diseases leads to incompatibility. Yet the race specific elicitors produced by the 'gene-for-gene' fungi Cladosporium fulvum (De Wit, Adv. Bot. Res. 21:147- 185, 1995) and Rhynchosporium secalis (Rohe et a1. , EMBO J.

Our lives and well being intimately depend on the exploitation of the plant genetic resources available to our breeding programs. Therefore, more extensive exploration and effective exploitation of plant genetic resources are essential prerequisites for the release of improved cultivars. Accordingly, the remarkable progress in genomics approaches and more recently in sequencing and bioinformatics offers unprecedented opportunities for mining germplasm collections, mapping and cloning loci of interest, identifying novel alleles and deploying them for breeding purposes. This book collects 48 highly interdisciplinary articles describing how genomics improves our capacity to characterize and harness natural and artificially induced variation in order to boost crop productivity and provide consumers with high-quality food. This book will be an invaluable reference for all those interested in managing, mining and harnessing the genetic richness of plant genetic resources.

The major objective of this book is to highlight the significance of phytonematodes in horticulture. Detailed and latest information on major aspects of phytonematodes associated exclusively with horticultural crops, which is the need of the day, is lacking. Hence, the book has been written mainly with the objective of providing its readers, comprehensive information on the advanced aspects related to phytonematodes associated with horticultural crops. It also provides basic information on plant parasitic nematodes since it is required for a better understanding of advanced topics. Several popular topics, information on which is already available in plenty, have been avoided. Thus, book explicates both the essential fundamental and advanced aspects pertaining to nematodes associated with horticultural crops. The book is conveniently divided into 13 chapters, which cover latest information on the major fundamental and advanced aspects related to phytonematodes including the role of phytonematodes in horticultural industry, phylogenetic and evolutionary concepts in nematodes, major phytonematodes associated with horticultural crops and their diagnostic keys, symptoms caused by phytonematodes and disease diagnosis, nematode population threshold levels, crop loss assessment, nematode diseases of horticultural crops and their management, nematode disease complexes, genetics of nematode parasitism, important nematological techniques and nematodes of quarantine importance. An exclusive chapter on novel methods of nematode management has been included mainly to provide the information on the latest molecules and novel modes of managing nematodes attacking horticultural crops. Routine nematode management aspects, information on which is already available, have not been discussed; instead, this topic reflects the changing scenario of future nematode management. Hence, this book can serve as a friendly guide to meet the requirements of the students, teachers and researchers interested in these 'hidden enemies' of the grower, apart from the research and extension personnel working under Public organizations, officials of State departments of Horticulture, Forestry, field workers and all those concerned and working with plant parasitic nematodes. Appropriate diagrams, convincing tables and suitable graphs/illustrations have been furnished at right places. A complete bibliography has also been included.

It appears that a comprehensive and up-to-date book on the impact of virus diseases on the major crops in developing countries is now much needed, especially as there have been rapid advances in the biological and molecular characterization and detection of the pathogens and possible approaches for their control. On the other hand, the economic losses caused by many of these diseases are tremendous and much of the accumulated knowledge to diminish the crop losses has not filtered through, or cannot be applied. This book is focused on the important crops. Each chapter on a specific crop will include inter alia, geographical distribution, the viruses - symptoms, damage, detection - a brief description of the viruses concerned, and present and future ways for their control. Experts from India, Nigeria, UK, USA, France, Germany, Peru, Japan, Australia, Netherlands, Venezuela, Kazakhstan and Israel (many of them from the International Research Institutions) have contributed chapters to this book.

This volume focuses on recent advances in the biochemical and molecular analysis of different families of phospholipases in plants and their roles in signaling plant growth, development and responses to abiotic and biotic cues.

The hydrolysis of membrane lipids by phospholipases produces different classes of lipid mediators, including phosphatidic acid, diacylglycerol, lysophospholipids, free fatty acids and oxylipins. Phospholipases are grouped into different families and subfamilies according to their site of hydrolysis, substrate usage and sequence similarities. Activating one or more of these enzymes often constitutes an early, critical step in many regulatory processes, such as signal transduction, vesicular trafficking, secretion and cytoskeletal rearrangements. Lipid-based signaling plays pivotal roles in plant stress responses, cell size, shape, growth, apoptosis, proliferation, and reproduction.

Microbial Phenazines: Biosynthesis, Agriculture and Health focuses on phenazines, a group of upwards of a hundred nitrogen-containing redox-active heterocyclic compounds of bacterial origin that have long attracted scientific interest because of their colorful pigmentation. Our understanding of these fascinating natural products and their role in human health and the environment has advanced rapidly in recent years, but we are only now beginning to be able to exploit the potential of these compounds in such fields as agriculture and medicine. This volume includes information on the biochemistry and genetics of phenazine synthesis, the physiological effects of phenazines, and methods for the isolation and identification of phenazines with the aid of spectroscopic and electrophoretic techniques. Also included are chapters focused on the roots of phenazine research in the biological control of plant pathogens and recent knowledge of the diversity of phenazine-producing microorganisms and the environments in which they occur. A final chapter addresses the potential of phenazines in the treatment of cancer.

Many fungi and bacteria that associate with plants are potentially harmful and can cause disease, while others enter into mutually beneficial sym bioses. Co-evolution of plants with pathogenic and symbiotic microbes has lead to refined mechanisms of reciprocal recognition, defense and counter defense. Genes in both partners determine and regulate these mechanisms. A detailed understanding of these genes provides basic biological insights as well as a starting point for developing novel methods of crop protection against pathogens. This volume deals with defense-related genes of plants and their regulation as well as with the genes of microbes involved in their interaction with plants. Our discussion begins at the level of populations and addresses the complex interaction of plant and microbial genes in multigenic disease resistance and its significance for crop protection as compared to mono genic resistance (Chap. 1). Although monogenic disease resistance may have its problems in the practice of crop protection, it is appealing to the experimentalist: in the so-called gene-for-gene systems, single genes in the plant and in the pathogen specify the compatibility or incompatibility of an interaction providing an ideal experimental system for studying events at the molecular level (Chaps. 2 and 4). Good progress has been made in identifying viral, bacterial, and fungal genes important in virulence and host range (Chaps. 3-6). An important aspect of plant-microbe interactions is the exchange of chemical signals. Microbes can respond to chemical signals of plant origin."

The offered volume intends to review the biological control theme of phytonematodes from several prospects: ecological; applicative as well as commercial state of the art; understanding the mode-of-action of various biocontrol systems; interaction between the plant host, nematodes surface and microorganism s; candidates for biocontrol; extrapolation of the wide knowledge existed in another systems for understanding biocontrol processes: "C. elegans" as a model and lessons from other natural systems; and exploiting advanced genomic tools to promote understanding biocontrol processes and thereafter improve specific biological control agents.

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This volume addresses the similarities and also the differences in the genomes of soil saprophytes, symbionts, and plant pathogens by using examples of fungal species to illustrate particular principles. It analyzes how the specific interactions with the hosts and the influence of the environment may have shaped genome evolution. The relevance of fungal genetic research and biotechnological applications is shown for areas such as plant pathogenesis, biomass degradation, litter decomposition, nitrogen assimilation, antibiotic production, mycoparasitism, energy, ecology, and also for soil fungi turning to human pathogens. In addition to the model organisms Neurospora and Aspergillus, the following species are covered providing a view of pathogens and mutualists: Trichoderma, Fusarium oxysporum, Cochliobolus heterostrophus, Penicillium chrysogenum, Rhizopus oryzae, Podospora anserina, and species belonging to Agaricomycetes, Archaeorhizomycetes and Magnaporthaceae. Ecology and potential applications have guided the choice of fungal genes to be studied and it will be fascinating to follow the trends of future sequencing projects.

Our view of plants is changing dramatically. Rather than being only slowly responding organisms, their signaling is often very fast and signals, both of endogenous and exogenous origin, spread throughout plant bodies rapidly. Higher plants coordinate and integrate their tissues and organs via sophisticated sensory systems, which sensitively screen both internal and external factors, feeding them information through both chemical and electrical systemic long-distance communication channels. This revolution in our understanding of higher plants started some twenty years ago with the discovery of systemin and rapid advances continue to be made. This volume captures the current 'state of the art' of this exciting topic in plant sciences.

Westcott's Plant Disease is a reference book on diseases which attack plants. Diseases of plants are found on most all plants including trees, shrubs, grasses, forage, fruits, vegetables, garden and greenhouse plants as well as native wild flowers and even weeds. Plant Disease Handbook identifies various types of diseases which are known to invade these plants located throughout North and South America. The recordings include diseases caused by fungi, bacteria, viruses, viroids and nematodes. Causal disease agents are described and illustrated in many cases and diseases and disease control measures are also discussed. A book such as this is never finished since new reports of diseases are continuously reported. This includes new diseases and previously known diseases which occur on both presently recorded plants and on new plants found to be susceptible to diseases. Westcott's Plant Disease provides a reference and guide for identification and control of these plant disease problems.

The explosive increase in the world's human population, with conse quent need to feed an ever-increasing number of hungry mouths, and the largely resultant disturbances and pollution of the environment in which man must live and produce the things he needs, are forcing him to search for means of solving the first problem without intensifying the latter. Food production requires adequate assurance against the ravages of insects. In the last three decades short-sighted, unilateral and almost exclusive employment of synthesized chemicals for insect pest control has posed an enormous and as yet unfathomed contribution to the degradation of our environment, while our insect pest problems seem greater than ever. Properly viewed, pest control is basically a question of applied ecology, yet its practice has long been conducted with little regard to real necessity for control, and in some cases, with little regard to various detrimental side-effects or long-term advantage with respect, even, to the specific crop itself. This book deals fundamentally with these questions. The development of pesticide resistance in many of the target species, against which the pesticides are directed, has occasioned an ever-increasing load of applications and complexes of different kinds of highly toxic materials. This has been made even more "necessary" as the destruction of natural enemies has resulted, as a side effect, in the rise to pest status of many species that were formerly innocuous. The application of broad-spec trum pesticides thus has many serious and self-defeating features."

This timely volume presents a comprehensive overview of the behavioral and physiological mechanisms underlying insect feeding. The single source for up-to-date information on the subject, it features contributions from the most authoritative scientists in the field worldwide. Taking an accessible approach focusing on the sequential stages of the feeding process, Regulatory Mechanisms in Insect Feeding explores the principles regulating feeding, and it offers information necessary for the development of more effective and environmentally safe methods to control the feeding of pest insects. The authors incorporate a spectrum of information in areas ranging from neurophysiology to insect control.An inclusive reference that reflects recent expansion and advances in the field, this book * considers the problems encountered by insects when feeding on different types of food, as well as their adaptations for dealing with the problems * introduces the cyclic nature of feeding activity and its components and provides the framework for the discussion of various control mechanisms * discusses the underlying regulatory mechanisms of feeding in both the short and long terms in insects with a diversity of feeding habits * synthesizes concepts and details of the basic mechanisms underlying insect feeding behavior that are essential for the development of pest management methods. Regulatory Mechanisms in Insect Feeding is the ideal text for graduate courses in entomology and zoology with a special focus on insect behavior, physiology, neurobiology, and control. It is also a valuable resource for ecologists interested in insect-plant and insect-animal interactions, for scientists concerned with the mechanisms behind the physiology and behavior of feeding, and for those working in crop protection and pest management.

Plant virus and sub-viral pathogens pose severe constraints to the production of wide range of economically important crops worldwide. The crops raised both through true seed and vegetative propagated materials are affected with number of virus and virus-like diseases. The virus may enter into plants through seed planting materials or by vectors. Once the virus is in the field, it multiplies and spreads following definite patterns depending upon the nature of the vector and agro-meteorological conditions. Disease free crops and plants are great economic and social importance in feeding the world's population. Detection of virus and sub-viral agents at initial stages of infection is critical to reduce economic losses. For nearly two decades, ELISA and its variants played a major role in large scale virus testing and also in the production of virus-free planting materials.

The theme of the book is highly relevant to the current emphasis on environment conservation, with focus on native biodiversity conservation in agro-ecosystems. The current impetus being given to organic farming and export oriented agri-hortculture in the country calls for access to relevant scientific knowledge base among the stakeholders. Research on biological pest control is more than a century old in India. Egg parasitoids, which are mainly tiny wasps, led by the family Trichogrammatidae, are the most widely utilized natural enemies for biological control globally. Over thirty countries are using these bioagents to protect over 10 million hectares of agricultural and forestry crops from many important insect pests. The book comprises 18 chapters, which are arranged in continuum, commencing with basic aspects of knowledge and ending in their utilization targets. The chapters cover broadly four areas: bio-diversity and natural occurrence of egg parasitoids, behaviour and adaptation of egg parasitoids, mass production and safe use of egg parasitoids and utilisation of egg parasitoids in different crop ecosystems. Some of the chapters cater to the needs of discipline-wise update on the current R&D scenario-like insect taxonomy, biotechnology, mass-production and quality control of the target organisms - egg-parasitoids, which are useful for laboratory scientists/researchers. There are also chapters devoted to knowledge status and scope for utilization of egg parasitoids in different target crops, which cater to requirements of field entomologists and extensionists for use in their tasks of guiding farmers/local guides. The book is different in approach, method, structure and content and ensures holistic coverage of the topic. The chapters are written by active and experienced workers in different crops and aspects and co-edited by four very experienced experts who have over three decades R&D experience in the subject. All the authors have uniformly focussed on comprehensive literature study and critical identification of knowledge gaps for future R&D, thus the book is novel in outlook, up-to-date in content and comprehensive in coverage of themes. This book will be useful for supplementary reading for MSc Agriculture and PhD Agriculture students, besides MSc/PhD research students in Zoology/Environmental Biology, who are specialising in Entomology. It would also serve as a very useful reference book for researchers worldwide, though focus is also there on Indian work. It addresses the special information needs of students and faculty, besides practitioners and extensionists in the Australasia and Africa regions and thus not limited to the R&D knowledge generated in developed countries.

The Handbook identifies all aspects of Regulatory Plant Biosecurity and discusses them from the standpoint of preventing the international movement of plant pests, diseases and weeds that negatively impact production agriculture, natural plant-resources and agricultural commerce.

The Trees and Shrubs manual is a reference manual on diseases which attack trees, shrubs, and vines. The manual identifies various types of diseases which are known to invade these plants located throughout North, Central, and South America. The recordings include diseases caused by fungi, bacteria, viruses, viroids, phytoplasmas, and nematodes. Causal disease agents are described and illustrated in some cases and diseases and disease control measures are also discussed. A manual such as this is never finished since new reports of diseases are continuously reported.

The Grasses and Native Plants manual is a reference manual on diseases which attack grasses, forage, native flowers, and weeds. The manual identifies various types of diseases which are known to invade these plants located throughout North, Central, and South America. The recordings include diseases caused by fungi, bacteria, viruses, viroids, phytoplasmas, and nematodes. Causal disease agents are described and illustrated in some cases and diseases and disease control measures are also discussed. A manual such as this is never finished since new reports of diseases are continuously reported.

This volume covers the high relevance of fungi for agriculture. It is a completely updated and revised second edition with fourteen excellent chapters by leading scientists in their fields and offers a comprehensive review of the latest achievements and developments. Topics include: Food and fodder; fungal secondary metabolites and detoxification; biology, disease control and management; symbiontic fungi and mycorrhiza; and phytopathogenicity.